Saints Row 2 is a "sandbox" game where you play as an escaped prisoner who must hijack cars, kill cops and other people, go to strip clubs, blow up helicopters, snap people's necks and complete violent missions.
You can even hold homeless people in front of you, like human shields, then toss them at their cardboard hang-outs - thereby killing the homeless people while also destroying their "homes."
Yes, this is insanely callous, but I would expect many Grand Theft Auto fans might enjoy Saints Row 2 more than they liked the last Grand Theft Auto IV, because GTA IV was rich in narrative and slower with violence. And there are many GTA fans who prefer gore to fancy storylines.
Yes, storylines exist in Saints Row 2. But it's all about the blood. When you blow off someone's head, the head explodes, blood splatters everywhere, and you hear a sound akin to a watermelon being sledge-hammered. It's nasty and gruesome, but it's also right up many people's alleys.